Emission Measurements on Electric Vehicle Charging Stations using a Battery Impedance Emulator

To improve the public acceptance of electric vehicles, the new EU commission is investing in charging infrastructure [1]. By increasing operating voltages to 800 V for vehicles [2] and to 1500 V for heavy duty and off-road trucks [3], the charging time can be decreased. Thus, the conducted electromagnetic emissions generated, which must comply with the emission limits in IEC 61851-21-2 [4] increase. In the standard a generic load is described in the exemplary setup with the main aim to sink the power generated by the charger. As the impedance of an electric vehicle battery differs much from an ohmic load, emulating this impedance is crucial to gain realistic results. To emulate an electric vehicle during the test, this work utilizes an inductively decoupled impedance measurement procedure [5], [6] to determine the impedances of three different electric vehicles [7]. The impedance of one vehicle is used to develop an impedance network. Finally, after a verification measurement, the network is compared to a passive load to point out the different results during conducted emission measurements with DC charging stations.